191680640 has 32 divisors (see below), whose sum is σ = 458238060. Its totient is φ = 76672000.

The previous prime is 191680639. The next prime is 191680651. The reversal of 191680640 is 46086191.

It can be written as a sum of positive squares in 2 ways, for example, as 176996416 + 14684224 = 13304^2 + 3832^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 191680640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149111 + ... + 150390.

Almost surely, 2^191680640 is an apocalyptic number.

191680640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191680640 is an abundant number, since it is smaller than the sum of its proper divisors (266557420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191680640 is an equidigital number, since it uses as much as digits as its factorization.

191680640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299520 (or 299508 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 191680640 is about 13844.8777531620. The cubic root of 191680640 is about 576.5797917102.

The spelling of 191680640 in words is "one hundred ninety-one million, six hundred eighty thousand, six hundred forty".